Please do this at your own risk, I will not be responsible for your mistakes or mishaps.
Id like to say thank you to Lermods for creating a very nice disco ball mod for our Pro models.
I think the latest code update made the disco insert flash instead of stay on solid causing spot and ball to pulse.
I spent the last few days pondering a solution.
What I came up with is a simple 1 solder joint and moving the photo sensor.
I started by opening up the black box, on the back of the larger board there is a black wire that goes to smaller 5v step down board.
This black wire needs to be moved from the far right terminal (1st pic) to the far left (2nd pic).
This essentially reverses the operation of the relays allowing disco mod to turn on when photo sensor sees no light.
Last step was to access bulb socket #154 under left katana ramp (at playfield level below the hammock). The sensor needs to be near that bulb.
I tapped it on to test but now have sensor just pinched between socket and the playfield up under left katana ramp
When disco multiball starts this bulb goes out triggering black box to turn on spot and disco ball.
There is one small issue right now where the disco insert blinks and reflects causing the ball and spot to blink.
I have ordered some #44 bulbs with a tap for another bulb.
Plan is to route those tap wires down below playfield and encase another led bulb with photo sensor in heatshrink to isolate the sensor.
This will fix the blinking from disco insert.
I will update photos and info when those parts are in.
Note that whenever Game is on and that GI bulb is out this mod is powered and will iluminate and spin.
Might not be what you want but its a quick fix.